Summary: Abstract -- Optical networks consist of switches that are con-
nected using fiber optics links. Each link consists of a set of wave-
lengths and each wavelength can be used by one or more users to
transmit information between two switches. In order to establish a
connection between the source and destination nodes, a set of
switches and links must be efficiently selected. This is known as the
routing problem. A wavelength is then assigned in each selected
link to establish the connection. This is known as the wavelength as-
signment problem. The problem of routing and wavelength assign-
ment (RWA) in optical networks has been shown to be NP-
Complete. In this paper, we propose a new approach to solving the
RWA problem using advanced Boolean satisfiability (SAT) tech-
niques. SAT has been heavily researched in the last few years. Sig-
nificant advances have been proposed and have lead to the
development of powerful SAT solvers that can handle very large
problems. SAT solvers use intelligent search algorithms that can
traverse the search space and efficiently prune parts that contain
no solutions. These solvers have recently been used to solve many
challenging problems in Engineering and Computer Science. In
this paper, we show how to formulate the RWA problem as a SAT